﻿#region COPYRIGHT
//--------------------------------------------------------------------------------
// <copyright file="PrimitiveTypeExtensions.cs" company="starLiGHT Entertainment Studios">
//    Copyright (c) 2007, 2008, 2009, 2010 
//       Roland Rosenkranz (Glatzemann@email.de)
// </copyright>
// <license>
//   This file is part of starLiGHT.Core.
//
//   starLiGHT.Core is free software: you can redistribute it and/or modify
//   it under the terms of the GNU Lesser General Public License as published by
//   the Free Software Foundation, either version 3 of the License, or
//   (at your option) any later version.
//
//   starLiGHT.Core is distributed in the hope that it will be useful,
//   but WITHOUT ANY WARRANTY; without even the implied warranty of
//   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//   GNU Lesser General Public License for more details.
//
//   You should have received a copy of the GNU Lesser General Public License
//   along with starLiGHT.Core. If not, see http://www.gnu.org/licenses/.
//    
//   ADDITIONAL (commercial) LICENSES for starLiGHT.Core are available on request.
// </license>
// <version>
// **************[ starLiGHT.Engine SVN ]**********************
// * $Rev:: 620                   $:  Revision of last commit *
// * $Author:: unknown            $:  Author of last commit   *
// * $Date:: 2010-12-07 15:23:58 #$:  Date of last commit     *
// ************************************************************
// </version>
//--------------------------------------------------------------------------------
#endregion

#if !ZUNE

namespace starLiGHT
{
    #region Using Statements
    using System;
    using Microsoft.Xna.Framework.Graphics;

    #endregion

    public static class RenderExtensionMethods
    {
        // Methods
        public static int ComputePrimitiveCount(this PrimitiveType primitiveType, int vertexCount)
        {
            switch (primitiveType)
            {
                case PrimitiveType.LineList:
                    return vertexCount / 2;

                case PrimitiveType.LineStrip:
                    return vertexCount - 1;

                case PrimitiveType.TriangleList:
                    return vertexCount / 3;

#if !XNA4
                case PrimitiveType.PointList:
                    return vertexCount;
                case PrimitiveType.TriangleStrip:
                case PrimitiveType.TriangleFan:
                    return vertexCount - 2;
#else
                case PrimitiveType.TriangleStrip:
                    return (vertexCount - 2);
#endif
            }

            throw new ArgumentException("unhandled primitive type", "primitiveType");
        }
    }
}

#endif